3 replies to this topic

[bewg]

Dear All,

I am in a project to select a gas treatment unit to process a stream of 0,5MMSCF of gas and almost 60%v of h2s, 20%v of H and no CO2 present, to produce a sweet gas with 150 ppm of h2s. The stream is available at a pressure of 100 psig and at ambient temperature (85°F approx.)

I had review all the technologies availables to treat sour gas but I could not find a precise operating conditions and h2s concentrations that could manage each process.

It is understood that absorption process are performed at high pressure, but:

For chemical absorption I have found that could operate from 60 to 2000 psig and up to 70%v of h2s concentration or a partial pressure of h2s of 80 psia in the feed gas, so I would like a more realistic numbers because is a big range the indicated above.

For physical absorption I have found that the contractor operates at 950-1000 psig and that is suitable for high partial pressure of the acid gas (more than 50 psia), but this could be achieved by a high total pressure or a high concentration (Pa=xaPt), so my question is what is more important the partial pressure or the total pressure for the contractor, because in my case I have an stream with a high concentration of H2s (Partial pressure is 60 psig) but the stream is at a low pressure, so I would need to compress the stream if I would like to use this type of technology?.

Thanks in advance

[balatpl]

Hi

Need to understand more of your feed.

1. What is the source of feed gas? Is the quantity 0.5 MMSCF per day or what?

2. What is the remaining 20% of it consist of?

3. After removing 60% of H2S, it seems you have 20% hydrogen left with. What is your plan with that?

[Mahdi1980]

You should prepare a data sheet including all the information of your feed and the desired values of composition at the outlet of H2S removal package. Then contact some vendors and let them recommend you regarding the best solution

[bewg]

Dear All,

 

Many thanks for your prompt reply and information. The flow is per day, 0,5MMSCFD, and the other components are hydrocarbons, C1-C4: 15% and C5+: 5%. The intent is to recover sulphur and sweet gas.

 

My main question is not regarding which technology is the best for the stream to be treat (I have already performed the technology selection and it is not an absorption process, I have contacted the vendors and I am waiting for their answers, however, I am open to any suggestion that you would share regarding this issue). My doubt is more general regarding the operating conditions of the absorption process with chemical or physical solvents for sweetening gas.

 

For physical absorption I would like to know what is more important: the partial pressure, the total pressure of the stream or the concentration of the sour gas, because it is understood that solubility increases with pressure but in the literature it is indicated that physical absorption is preferable when you have high sour gas partial pressure (but this is a combination of total pressure and concentration) and they also say that the absorption is performed at 1000 psig. In my case I comply with the high partial pressure requirement but what I want to know is if I also need to compress the stream before the absorption (chemical or physical).

 

Many thanks in advance,

 

 

 

 

 

The flow is per day, 0,5MMSCFD, and the other components are hydrocarbons, C1-C4: 15% and C5+: 5%.